The field of the present invention is body motion isolating systems for mounting a camera.
In the mid-1970's, mounting systems were developed for motion picture cameras which were used to mount the camera on the body of an operator. These systems were designed to very substantially isolate the motion of the supporting body from the camera. At the same time, the systems provided suspending support for the camera. The supported camera was capable of being lightly guided by the hand of the operator who could move the camera horizontally in all directions either relative to his body or with his body as he moved about. The camera could also be raised or lowered with a relatively light touch. A number of patents have issued on these early systems. They include U.S. Pat. Nos. 4,017,168; 4,156,512; 4,208,028 and 4,394,075. the disclosures of which are incorporated herein by reference.
More recently, refinements to such systems have been considered. Of particular interest is the versatility of the equipment to accommodate different amounts of load. A number of possible load requirements may be contemplated. A trial video image may be desired which would require a relatively light video camera. A much heavier film camera might then be contemplated for the actual image production. Accessories such as stabilizing flywheels, batteries, monitors and the like also may be needed for particular sequences. Thus, a range of support forces can be required.
The performance of such support systems under widely varying load conditions is complex. Through preloading of resilient systems such as springs, the static support weight can be easily accommodated. However, the profile of lifting support across a vertical range of motion can be greatly affected by changes in load. These changes can place the response of the system outside of the acceptable range for operation. Reconfiguration and tuning of the system on location to accommodate such changes in load have been found inconvenient and often unacceptable.
One mechanism which has been devised for adjusting both the load capacity and the profile of load support with vertical motion is disclosed in U.S. Pat. No. 5,435,515, the disclosure of which is incorporated herein by reference. In this system, the support structure geometry is altered through adjustments to the mountings for the resilient force generating elements.
The load to be carried typically includes a tube chassis with a camera platform at the upper end and batteries and other elements at the other. The tube chassis has a handle for manipulating the assembly. A three-axis gimbal mechanism is attached to the tube chassis near but above the center of gravity. The gimbal mechanism is supported by the support system. One such assembly including a tube chassis and three-axis gimbal mechanism is illustrated in U.S. patent application Ser. No. 08/746,204, filed Nov. 6, 1996, now U.S. Pat. No. 5,752,112, the disclosure of which is incorporated herein by reference.